Patent Grant
10870439
The present disclosure relates to a vehicle wheel support device supporting a wheel for a railway vehicle and a vehicle including the vehicle wheel support device.
Many railway vehicles include a bogie having a structure in which: two wheels are fitted to both ends of each of two wheel shafts with the two wheels separated from each other depending on a track gauge between two rails; and the two wheel shafts with the wheels are arranged on the front side and on the rear side with respect to a direction of travel of a railway vehicle and are supported by a bogie frame. The four wheels are attached to this bogie. A railway vehicle has a configuration in which two bogies, each including two wheel shafts with wheels, are arranged on the front and rear sides of the railway vehicle, and a vehicle body is mounted on the two bogies with the vehicle body straddling the two bogies. In this case, the wheels are supported by fitting the wheels to the wheel shafts.
Recently, a lightweight low-floor vehicle is used for inner-city traffic. Due to lowering of the vehicle floor, a wheel shaft to which the right and left wheels are fixed is not used, but rather a method is used that supports the right and left wheels independently. In this structure, the right-side wheel and the left-side wheel are configured to be rotated separately from each other as the right-side wheel and the left-side wheel are not interconnected. A motor for driving the right-side wheel is different from a motor for driving the left-side wheel, and the right-side wheel and the left-side wheel are controlled separately from each other.
A conventional bogie for independent wheel drive has a structure in which wheels each of which can be individually and separately rotated are arranged on the right side and the left side of a bogie frame. Motors arranged on the right side and the left side of the bogie frame separately drive the wheels arranged on the right side and on the left side. A vehicle with such a conventional bogie can run on rails by rotational driving of the wheels.
For example, a component for independent wheel drive disclosed in Patent Literature 1 has a structure in which each of wheels can be separately rotated. In the component of Patent Literature 1, rotary speeds of motors are decreased by planetary reduction gears and torques of the motors are respectively transmitted through transmission elements to the wheels. A plurality of insertion holes is formed in each of the wheels, pin portions of the transmission elements are inserted into the insertion holes of the wheels, and ring-shaped anti-vibration elements are placed between the insertion holes and the pin portions. Torques from the motors are reliably transmitted to the wheels due to compression of the anti-vibration elements. Also, the anti-vibration elements reduce radial vibration occurring in the wheels.
Patent Literature 1: Unexamined Japanese Patent Application Kokai Publication No. 2000-309268
The bogie for independent wheel drive disclosed in Patent Literature 1 has a structure in which support of wheels is performed using shafts, each protruding outward from a bogie frame in a width direction of a vehicle body, and four wheels for the bogie are supported by the integrated bogie frame. As a result, the device disclosed in Patent Literature 1 has problems in that the bogie using the device of Patent Literature 1 has a large total mass, unsprung mass of the vehicle is hard to reduce, and there is a limitation in lowering of a vehicle body floor between the right-side and left-side wheels.
The present disclosure is made in order to solve the aforementioned problems, and thus an objective of the present disclosure is to reduce unsprung mass and to lower the vehicle body floor between wheels.
A vehicle wheel support device of the present disclosure is a vehicle wheel support device for supporting wheels of a vehicle that runs on a railroad track including two rails laid parallel to each other. The vehicle wheel support device includes a first support frame, a second support frame, first to fourth L-shaped links, first to fourth support links.
The first support frame rotatably supports a first wheel in such a manner that the first wheel can roll on one of the rails and supports a vehicle body of the vehicle through a suspension system. The second support frame rotatably supports a second wheel facing the first wheel in a lateral direction orthogonal to a traveling direction of the vehicle in such a manner that the second wheel can roll on another of the rails, is arranged separately from the first support frame and supports the vehicle body through a suspension system.
Middle bending portions of the first to fourth L-shaped links are pivotally supported by the vehicle body, and upper ends of the first to fourth L-shaped links are pivotally joined to the first to fourth support links.
Lower ends of the first and third L-shaped links are pivotally supported by a lower portion of the first support frame, and lower ends of the second and fourth L-shaped links are pivotally supported by a lower portion of the second support frame.
One ends of the first and third support links are pivotally joined to the upper ends of the first and third L-shaped links, and the other ends of the first and third support links are pivotally supported by upper portions of the second support frame. One ends of the second and fourth support links are pivotally joined to the upper ends of the second and fourth L-shaped links, and the other ends of the second and fourth support links are pivotally supported by upper portions of the first support frame.
The vehicle wheel support device according to the present disclosure has a structure in which the support frames are directly supported by the vehicle body via a plurality of types of links so that the vehicle wheel support device does not include a bogie frame having large mass, thereby having an effect of reducing unsprung mass of the vehicle. Also, in the present disclosure, the components supporting the links are attached to the vehicle body, and thus the present disclosure has an effect of enabling lowered setting of the gap that allows relative movement between the vehicle body and the links, and enabling further lowering of the floor of the vehicle body.
Embodiments of the present disclosure are described in detail hereinafter with reference to drawings. Components that are the same or equivalent are assigned the same reference signs throughout the drawings. Also, in order to avoid complication of the figures and to facilitate understanding, there are cases in which bolts, nuts, holes through which bolts are passed, and the like are omitted from the figures.
A vehicle wheel support device 70 according to Embodiment 1 of the present disclosure is used for the vehicle running on a railroad track including two rails laid parallel to each other. In the specification, terms related to the railroad track are defined as follows: a railroad track plane is defined as a plane that touches upper surfaces of the two rails; a vertical direction is defined as a direction perpendicular to the railroad track plane; front-rear direction is defined as a direction parallel to a traveling direction of the vehicle running on the railroad track; and a lateral direction is defined as a direction parallel to the railroad track plane and orthogonal to the traveling direction of the vehicle.
The vehicle wheel support device 70 according to Embodiment 1 includes a support frame 4a as a first support frame and a support frame 4b as a second support frame, and the support frames 4a and 4b rotatably support a wheel 5a as a first wheel and a wheel 5b as a second wheel in such a manner that: the wheels 5a and 5b face each other in the lateral direction; and the wheels 5a can roll on one of the two rails and the wheel 5b can roll on the other of the two rails. Also, the support frames 4a and 4b support the vehicle body 1 of the vehicle 80 via a suspension system 8. The support frames 4a and 4b respectively support one wheel 5a and one wheel 5b, and the support frames 4a and 4b are separated from each other with respect to the lateral direction. Four sets of a L-shaped link and a linear link are used with respect to displacements of the two support frames 4a and 4b relative to the vehicle body 1 in the traverse direction of the vehicle. The vehicle wheel support device 70 transmits forces between the vehicle body 1 and the supports frames 4a and 4b using four traction links, the directions of the forces being the front-rear directions of the vehicle.
A planetary gear device 2 and a driving motor 3 are fixed to each of the support frames 4a and 4b and are coaxial with the respective wheel 5a or 5b. A rotary shaft of the driving motor 3 is joined to an input shaft of the planetary gear device 2, and an output shaft of the planetary gear device 2 is joined to the wheel 5a or 5b. The wheels 5a and 5b are rotated by driving forces of the driving motors 3.
The support frame 4a is arranged farther from the rail thereof than the wheel 5a and supports the wheel 5a in such a manner that the wheel 5a can roll on the rail thereof, and the support frame 4b is arranged farther from the rail thereof than the wheel 5b and supports the wheel 5b in such a manner that the wheel 5b can roll on the rail thereof. L-shaped links 6a, 6b, 6c and 6d are respectively supported by L-shaped link-supporting portions 1a, 1b, 1c and 1d of the vehicle body in such a manner that the L-shaped links 6a, 6b, 6c and 6d can respectively pivot about shafts that are located in respective middle bending portions of the L-shaped links 6a, 6b, 6c and 6d and that run in the front-rear direction. The L-shaped link-supporting portions 1a, 1b, 1c and 1d are omitted from
The L-shaped link 6a as a first L-shaped link is joined to the support frame 4a below the central axis of the wheel 5a and forward of the central axis of the wheel 5a with respect to the front-rear direction in such a manner that the L-shaped link 6a can pivot about a shaft running in the front-rear direction. Also, the L-shaped link 6a is supported by the L-shaped link-supporting portion 1a of the vehicle body 1 below the central axis of the wheel 5b and forward of the central axis of the wheel 5b with respect to the front-rear direction on the wheel 5b-side with respect to the center line between the two rails in such a manner that the L-shaped link 6a can pivot about a shaft running in the front-rear direction. The L-shaped link 6b as a second L-shaped link is joined to the support frame 4b below the central axis of the wheel 5b and forward of the central axis of the wheel 5b with respect to the front-rear direction in such a manner that the L-shaped link 6b can pivot about a shaft running in the front-rear direction. Also, the L-shaped link 6b is supported by the L-shaped link-supporting portion 1b of the vehicle body 1 below the central axis of the wheel 5a and forward of the central axis of the wheel 5a with respect to the front-rear direction on the wheel 5a-side with respect to the center line between the two rails in such a manner that the L-shaped link 6b can pivot about a shaft running in the front-rear direction. The L-shaped link 6c as a third L-shaped link is joined to the support frame 4a below the central axis of the wheel 5a and reward of the central axis of the wheel 5a with respect to the front-rear direction in such a manner that the L-shaped link 6c can pivot about a shaft running in the front-rear direction. Also, the L-shaped link 6c is supported by the L-shaped link-supporting portion 1c of the vehicle body 1 below the central axis of the wheel 5b and reward of the central axis of the wheel 5b with respect to the front-rear direction on the wheel 5b-side with respect to the center line between the two rails in such a manner that the L-shaped link 6c can pivot about a shaft running in the front-rear direction. The L-shaped link 6d as a fourth L-shaped link is joined to the support frame 4b below the central axis of the wheel 5b and reward of the central axis of the wheel 5b with respect to the front-rear direction in such a manner that the L-shaped link 6d can pivot about a shaft running in the front-rear direction. Also, the L-shaped link 6d is supported by the L-shaped link-supporting portion 1d of the vehicle body 1 below the central axis of the wheel 5a and reward of the central axis of the wheel 5a with respect to the front-rear direction on the wheel 5a-side with respect to the center line between the two rails in such a manner that the L-shaped link 6d can pivot about a shaft running in the front-rear direction.
The support link 7a that is a first support link extending from the support frame 4b toward the wheel 5a-side is joined, pivotally about a shaft running in the front-rear direction, to the support frame 4b above the central axis of the wheel 5b and forward of the central axis of the wheel 5b with respect to the front-rear direction. The support link 7b that is a second support link extending from the support frame 4a toward the wheel 5b-side is joined, pivotally about a shaft running in the front-rear direction, to the support frame 4a above the central axis of the wheel 5a and forward of the central axis of the wheel 5a with respect to the front-rear direction. The support link 7c that is a third support link extending from the support frame 4b toward the wheel 5a-side is joined, pivotally about a shaft running in the front-rear direction, to the support frame 4b above the central axis of the wheel 5b and reward of the central axis of the wheel 5b with respect to the front-rear direction. The support link 7d that is a fourth support link extending from the support frame 4a toward the wheel 5b-side is joined, pivotally about a shaft running in the front-rear direction, to the support frame 4a above the central axis of the wheel 5a and reward of the central axis of the wheel 5a with respect to the front-rear direction.
The lower traction link 10a that is a first lower traction link extending in the front-rear direction is joined, pivotally about a shaft running in the lateral direction, to the support frame 4a below the central axis of the wheel 5a in such a manner that the lower traction link 10a can pivot. Also, the lower traction link 10a is supported by the vehicle body 1 pivotally about a shaft running in the lateral direction. The lower traction link 10b that is a second lower traction link extending in the front-rear direction is joined, pivotally about a shaft running in the lateral direction, to the support frame 4b below the central axis of the wheel 5b. Also, the lower traction link 10b is supported by the vehicle body 1 pivotally about a shaft running in the lateral direction. The upper traction link 9a that is a first upper traction link extending in the front-rear direction is joined, pivotally about a shaft running in the lateral direction, to the support frame 4a above the central axis of the wheel 5a. Also, the upper traction link 9a is supported by the vehicle body 1 pivotally about a shaft running in the lateral direction. The upper traction link 9b that is a second upper traction link extending in the front-rear direction is joined, pivotally about a shaft running in the lateral direction, to the support frame 4b above the central axis of the wheel 5b. Also, the upper traction link 9b is supported by the vehicle body 1 pivotally about a shaft running in the lateral direction. Portions of the vehicle body 1 by which the lower traction links 10a and 10b and the upper traction links 9a and 9b are supported are not illustrated in the drawings.
The L-shaped link 6a is joined, pivotally about a shaft running in the front-rear direction, to the support link 7a above the central axis of the wheel 5b and forward of the central axis of the wheel 5b with respect to the front-rear direction. The L-shaped link 6b is joined, pivotally about a shaft running in the front-rear direction, to the support link 7b above the central axis of the wheel 5a and forward of the central axis of the wheel 5a with respect to the front-rear direction. The L-shaped link 6c is joined, pivotally about a shaft running in the front-rear direction, to the support link 7c above the central axis of the wheel 5b and reward of the central axis of the wheel 5b with respect to the front-rear direction. The L-shaped link 6d is joined, pivotally about a shaft running in the front-rear direction, to the support link 7d above the central axis of the wheel 5a and reward of the central axis of the wheel 5a with respect to the front-rear direction.
In Embodiment 1, the L-shaped links 6a and 6c are similar to each other in shape. One of the L-shaped links 6a and 6c is arranged forward of the wheels 5a and 5b and the other of the L-shaped links 6a and 6c is arranged reward of the wheels 5a and 5b. The L-shaped links 6b and 6d are similar to each other in shape. One of the L-shaped links 6b and 6d is arranged forward of the wheels 5a and 5b and the other of the L-shaped links 6b and 6d is arranged reward of the wheels 5a and 5b. Moreover, in Embodiment 1, the L-shaped links 6a, 6b, 6c and 6d are similar to one another in shape.
The support link 7b (7a) and the support link 7d (7c) are pivotally joined to support frame upper portion-supporting portions 21 illustrated in
The support frame 4a (4b) is subjected axially to a lateral load from the wheel 5a (5b) when the vehicle travels. Therefore, reinforcing plates 19 and 20 are fixed to a portion of the support frame 4a (4b) on the side on which the wheel 5a (5b) is attached and reinforcing plates 26 and 27 are fixed to a portion of the support frame 4a (4b) on the side on which the driving motor 3 is attached. Mounting boards 24 on which the suspension systems 8 are mounted are fixed to the support frame 4a (4b) on the side on which the driving motor 3 is attached. The vehicle body 1 is supported via the suspension systems 8 mounted on the mounting boards 24. The suspension systems 8 are, for example, air suspensions. For example, the air suspensions are fixed to the support frame 4a (4b) by passing bolts into bolt holes formed on the mounting boards 24 and by fastening the bolts from the lower side. Examples of the suspension systems 8 that can be used for the present disclosure include not only the air suspension but also a laminated leaf spring and a combination of a coil spring and a damper.
For the movement of the support frame 4a (4b) relative to the vehicle body 1 in the front-rear direction of the vehicle, the upper traction link 9a (9b) and the lower traction link 10a (10b) are each attached to the support frame 4a (4b) that is arranged in the lateral direction. One end of the upper traction link 9a (9b) is joined, pivotally about a shaft running in the lateral direction, to one of two upper traction link-supporting portions 29. The other end of the upper traction link 9a (9b) is joined, pivotally about a shaft running in the lateral direction, to the vehicle body 1. One end of the lower traction link 10a (10b) is joined, pivotally about a shaft running in the lateral direction, to one of two lower traction link-supporting portions 30 illustrated in
As illustrated in
Next, a structure for supporting the support frames 4a and 4b from the vehicle body 1-side is described.
The L-shaped links 6a and 6b are arranged between the lateral support frames 4a and 4b, and the middle bending portions of the L-shaped links 6a and 6b are provided with L-shaped link-supporting shafts 31a and 31b that are supported pivotally around axes running from the vehicle body 1 in the front-rear direction. One end of the L-shaped link 6a extending from the L-shaped link-supporting shaft 31a in the lateral direction is provided with a support frame lower portion joining shaft 32a that is joined, pivotally about an axis running in the front-rear direction, to the support frame lower portion-supporting portion 28 of the support frame 4a. One end of the L-shaped link 6b extending from the L-shaped link-supporting shaft 31b in the lateral direction is provided with a support frame lower portion joining shaft 32b that is joined, pivotally about an axis running in the front-rear direction, to the support frame lower portion-supporting portion 28 of the support frame 4b. The other end of the L-shaped link 6a extending from the L-shaped link-supporting shaft 31a in the vertical direction is provided with a link-jointing shaft 33a that is joined, pivotally about an axis running in the front-rear direction, to one end of the support link 7a. The other end of the L-shaped link 6b extending from the L-shaped link-supporting shaft 31b in the vertical direction is provided with a link-jointing shaft 33b that is joined, pivotally about an axis running in the front-rear direction, to one end of the support link 7b. The other ends of the support links 7a and 7b are respectively provided with support frame upper portion-joining shafts 34a and 34b that are respectively joined, pivotally about axes running in the front-rear direction, to the support frame upper portion-supporting portions 21 of the support frames 4a and 4b. The L-shaped link 6a and the support link 7a are joined, pivotally about an axis running in the front-rear direction, to the link-jointing shaft 33a. The L-shaped link 6b and the support link 7b are joined, pivotally about an axis running in the front-rear direction, to the link-jointing shaft 33b. As illustrated in
When the vehicle travels on a railroad track, in addition to motion of the vehicle body 1 in the front-rear direction which is caused by acceleration of or braking of the vehicle, the vehicle body 1 is also subjected to a force in the plane orthogonal to the front-rear direction, thereby causing a displacement of the vehicle body 1 relative to the wheels 5a and 5b in the plane orthogonal to the front-rear direction. An up-and-down movement of the vehicle 1 is caused by simultaneous and samely-directed bumpy movements of both the wheels 5a and 5b relative to the vehicle body 1. For example, a downward movement of the vehicle body 1 can be regarded as simultaneous upward movements of both the wheels 5a and 5b relative to the vehicle body 1. In this case, the support frame lower portion-joining shaft 32a of the lower end of the L-shaped link 6a pivotally joined to the left-side support frame 4a moves upward in a circular arc, the center of which is the L-shaped link-supporting shaft 31a of the middle bending portion of the L-shaped link 6a. Also, the support frame lower portion-joining shaft 32b of the lower end of the L-shaped link 6b pivotally joined to the right-side support frame 4b moves upward in a circular arc, the center of which is the L-shaped link-supporting shaft 31b of the middle bending portion of the L-shaped link 6b, like the support frame lower portion-joining shaft 32a of the lower end of the L-shaped link 6a.
The link-jointing shaft 33a of the other end of the L-shaped link 6a moves to the support frame 4b-side in a circular arc, the center of which is the L-shaped link-supporting shaft 31a, in response to the above movement of the support frame lower portion-joining shaft 32a. The link-jointing shaft 33b of the other end of the L-shaped link 6b moves to the support frame 4a-side in a circular arc, the center of which is the L-shaped link-supporting shaft 31b, in response to the above movement of the support frame lower portion-joining shaft 32b. The ranges of the up-and-down movements of the wheels 5a and 5b are smaller than the distance from the support frame lower portion joining shaft 32a to the L-shaped link-supporting shaft 31a in the L-shaped link 6a and the distance from the support frame lower portion joining shaft 32b to the L-shaped link-supporting shaft 31b in the L-shaped link 6b, so that amounts of the transversely horizontal movements of the support frame lower portion-joining shafts 32a and 32b caused by the up-and down movements of the wheels 5a and 5b is extremely small.
When the wheels 5a and 5b move upward relative to the vehicle body 1, the link-jointing shafts 33a and 33b of the L-shaped links 6a and 6b move to the outside as described above. The support frame upper portion-joining shafts 34a and 34b of the support frames 4a and 4b support the link-jointing shafts 33a and 33b via the support links 7a and 7b that make angles with the horizontal. Therefore, when the movements of the link-jointing shafts 33a and 33b to the outside and the upward movements of the support frame lower portion-joining shafts 32a and 32b simultaneously occur, amounts of the transversely horizontal movements of the support frame upper portion-joining shafts 34a and 34b of the support frames 4a and 4b are small. As a result, the inclinations of the support frames 4a and 4b are nearly unchanged and thus can be maintained. Due to simultaneous upward movements of the left-side and right-side wheels 5a and 5b, the railroad track plane also move parallel with the railroad track plane keeping parallel to the central axes of the wheels 5a and 5b, and the wheels 5a and 5b move up and down with rotation planes thereof maintained nearly perpendicular to the railroad track plane.
In the case where a rolling motion of the vehicle body 1 occurs, up-and-down movements of the left-side wheel 5a relative to the vehicle body 1 are different from up-and-down movements of the right-side wheel 5b relative to the vehicle body 1. For example, in the case where the vehicle body 1 pivots about the wheel 5b to slant to the wheel 5a-side, up-and-down movements of the right-side wheel 5b relative to the vehicle body 1 do not occur, and only the left-side wheel 5a can be regarded as moving upward relative to the vehicle body 1. In this case, neither the support frame lower portion-joining shaft 32b arranged in the lower portion of the right-side support frame 4b nor the link-jointing shaft 33b of the other end of the L-shaped link 6b moves.
The left-side support frame 4a moves upward, the support frame lower portion joining shaft 32a moves upward in an circular arc, the center of which is the L-shaped link-supporting shaft 31a of the L-shaped link 6a, and the link-jointing shaft 33a of the other end of the L-shaped link 6a moves to the right side. The amounts of the up-and-down movements of the support frame lower portion-joining shaft 32a are extremely smaller compared to the distance from the support frame lower portion-joining shaft 32a of the L-shaped link 6a to the L-shaped link-supporting shaft 31a of the L-shaped link 6a, and thus an amount of transversely horizontal movement of the support frame lower portion joining shaft 32a is small even though the support frame lower portion-joining shaft 32a moves in a circular arc. In the left-side support frame 4a, the support frame lower portion-joining shaft 32a moves nearly upward, and the inclination angle of the support link 7b causes the support frame upper portion-joining shaft 34a to pivot about the link-jointing shaft 33b that is immovable, thereby causing both upward and rightward movements of the support frame upper portion-joining shaft 34a. As a result, the support frame 4a inclines to the right side.
However, in the right-side support frame 4b, the support frame lower portion-joining shaft 32b arranged in the lower portion of the support frame 4b does not move but the link-jointing shaft 33a of the L-shaped link 6a moves to the right side. Therefore, the support frame upper portion joining shaft 34b of the support frame 4b is moved to the right side by the support link 7a. As a result, the support frame 4b also inclines to the right side. Although the up-and down movements of the right-side wheel 5b relative to the vehicle body 1 does not occur, the left-side wheel 5a moves upward, thereby the railroad track plane changes from a state in which the railroad track plane is in a horizontal position to a state in which the railroad track plane inclines to the right side, and both the left-side support frame 4a and the right-side support frame 4b incline to the right side. Therefore, also in this case, both the planes of rotation of the wheels 5a and 5b are kept nearly perpendicular to the railroad track plane.
Various movements of the vehicle body 1 including the up-and-down movements thereof and the rolling motion thereof can be expressed by the sum of the above-described simultaneous up-and-down movements of the wheels 5a and 5b and the above-described up-and-down movements of only one of the wheels 5a and 5b. As described above, both in the case of occurrence of simultaneous the up-and-down movements of the wheels 5a and 5b and in the case of occurrence of the up-and-down movements of only one of the wheels 5a and 5b, both the planes of rotation of the wheels 5a and 5b can be kept nearly perpendicular to the railroad track plane, and thus even when these movements are combined, both the planes of rotation of the wheels 5a and 5b can be kept nearly perpendicular to the railroad track plane.
As described above, the vehicle wheel support device 70 of Embodiment 1 has an effect enabling both the wheels 5a and 5b to be maintained nearly perpendicularly to the railroad track plane regardless of how the vehicle body 1 moves. However, a degree of a change in inclination angles of the wheels 5a and 5b with the railroad track plane and a degree of a change in distance between the wheels 5a and 5b vary in accordance with setting of the distance between the L-shaped link-supporting shafts 31a and 31b, the distance from the L-shaped link-supporting shaft 31a to the support frame lower portion-joining shaft 32a, the distance from the L-shaped link-supporting shaft 31b to the support frame lower portion joining shaft 32b, the distance from the L-shaped link-supporting shaft 31a to the link-jointing shaft 33a, the distance from the L-shaped link-supporting shaft 31b to the link-jointing shaft 33b, the distance from the link-jointing shaft 33a to the support frame upper portion-joining shaft 34a, the distance from the link-jointing shaft 33b to the support frame upper portion-joining shaft 34b, the distance from the support frame lower portion-joining shaft 32a to the support frame upper portion joining shaft 34a, and the distance from the support frame lower portion-joining shaft 32b to the support frame upper portion joining shaft 34b.
The distance between the L-shaped link-supporting shafts 31a and 31b is expressed by the symbol “L1”, the distance from the L-shaped link-supporting shaft 31a of the L-shaped link 6a to the support frame lower portion-joining shaft 32a is expressed by the symbol “L2”, the distance from the L-shaped link-supporting shaft 31a of the L-shaped link 6a to the link-jointing shaft 33a is expressed by the symbol “L3”, the distance from the link-jointing shaft 33a of the support link 7a to the support frame upper portion-joining shaft 34a is expressed by the symbol “L4”, the distance from the support frame lower portion-joining shaft 32a of the support frame 4a to the support frame upper portion-joining shaft 34a is expressed by the symbol “L5”, and an angle between the shortest line segment from the support frame lower portion-joining shaft 32a of the L-shaped link 6a to the L-shaped link-supporting shaft 31a of the L-shaped link 6a and the shortest line segment from the L-shaped link-supporting shaft 31a of the L-shaped link 6a to the link-jointing shaft 33a of the L-shaped link 6a is expressed by the symbol, “φ”. The distances between the corresponding pivot junction of the L-shaped links 6b, 6c and 6d and the angles between the shortest line segments between the corresponding pivot junction of the L-shaped links 6b, 6c and 6d are respectively the same as the distances between the above pivot junction of the L-shaped link 6a and the angle between the shortest line segments between the above pivot junction of the L-shaped link 6a, and the distances between the corresponding pivot junction of the support links 7b, 7c and 7d are the same as the distances between the above pivot junction of the support link 7a. Therefore, the distances between the corresponding pivot junction of the L-shaped links 6b, 6c and 6d and the support links 7b, 7c and 7d and the angles between the shortest segments between the corresponding pivot junction of the L-shaped links 6b, 6c and 6d are also respectively expressed by the symbols, “L1” to “L5” and “φ”.
For a combination of the distances L2, L3, L4 and L5 and the angle φ when the distance L1 between the L-shaped link-supporting shafts 31a and 31b is set in accordance with a track gauge of the railroad track on which a vehicle provided with the vehicle wheel support device 70 travels, numerical calculations can be performed to calculate a change in a distance between the wheels 5a and 5b that is a wheel distance in the case where the up-and-down movements of wheels 5a and 5b in the same direction or in opposite directions occur and a change in angles with the railroad track plane which the wheels 5a and 5b make. For combinations of values obtained by varying the distances L2 to L5 and the angle φ within possible ranges of the distances L2 to L5 and the angle φ and under constraint conditions thereof, a change in distance between the wheels 5a and 5b due to up-and-down movements of the wheels 5a and 5b and a change in angles with the railroad track plane which the wheels 5a and 5b make are calculated, and the combination of values of the distances L2 to L5 and the angle φ is found for which the calculated change in distance between the wheels 5a and 5b and the calculated change in angles with the railroad track plane have the minimum values. Therefore, the vehicle wheel support device 70 can be made by forming the support frames 4a and 4b, the L-shaped links 6a, 6b, 6c and 6d and support links 7a, 7b, 7c and 7d that can achieve the set value of the wheel distance L1 and the values of the distances L2 to L5 and the angle φ at which the change in wheel distance due to up-and-down movements of the wheels 5a and 5b and the change in angles with the railroad track vehicle which the wheels 5a and 5b make have the minimum values.
The L-shaped link-supporting shafts 31a and 31b of the L-shaped links 6a and 6b are supported by the vehicle body 1 so as not to move relative to the vehicle body 1 in the vertical direction. Depending on the matter of setting the length of the L-shaped link 6a between the L-shaped link-supporting shaft 31a and the support frame lower portion-joining shaft 32a and the length of the L-shaped link 6b between the L-shaped link-supporting shaft 31b and the support frame lower portion joining shaft 32b, a vertical distance from the railroad track plane to a floor plane of the vehicle body in a low floor portion of the vehicle body between the wheels 5a and 5b is the sum of the minimum necessary vertical distance from the railroad track plane to the bottom of the vehicle body, a minimum necessary space for the L-shaped link-supporting shafts 31a and 31b of the L-shaped links 6a and 6b, and the thickness of the low floor portion of the vehicle body. Unlike conventional configurations used in the prior art, the configuration of the vehicle wheel support device 70 according to Embodiment 1 does not require any space necessary for relative up-and-down movements of the bogie frame supporting the wheels 5a and 5b relative to the vehicle body and thus makes possible achievement of a lower vertical distance between the floor plane of the vehicle body and the railroad track plane compared with vehicles using the conventional techniques.
As described above, in the vehicle wheel support device 70 according Embodiment 1, the support frames 4a and 4b rotatably supporting the wheels 5a and 5b are respectively arranged to the outside of the wheels 5a and 5b, the L-shaped links 6a, 6b, 6c and 6d are pivotally supported by the vehicle body 1 via the middle bending portions of the L-shaped links 6a, 6b, 6c and 6d, the L-shaped links 6a, 6b, 6c and 6d are pivotally joined to the support frames 4a and 4b via the support frame lower portion joining shafts 32a and 32b and to one ends of the support links 7a, 7b, 7c and 7d via the link-jointing shafts 33a and 33b. The other ends of the support links 7a, 7b, 7c and 7d are pivotally joined to the support frame upper portion-joining shafts 34a and 34b of the support frames 4a and 4b. The vehicle wheel support device 70 used for the vehicle 80 is configured by pivotally joining the upper traction link 9a and the lower traction links 10a to the support frame 4a and pivotally joining the upper traction link 9b and the lower traction links 10b to the support frame 4b. Therefore, in the vehicle wheel support device 70 according to Embodiment 1, defining distances between pivot junctions in accordance with selected values of the distance between the L-shaped link-supporting shafts 31a and 31b of the L-shaped links 6a and 6b enables a remarkable reduction in a change in distance between the wheels 5a and 5b due to up-and-down movements of the vehicle body 1 and a change in angles with the railroad track plane which the wheels 5a and 5b make. Therefore, while maintaining conditions similar to those of a generally-used railroad vehicle using the wheels integrated with the wheel shaft, upsprung mass of the vehicle can be reduced and a floor plane of the vehicle body between the wheels can be made to become close to the railroad track plane.
In
Also, in
In the vehicle wheel support device 70 according to Embodiment 1, as illustrated in
The position of the L-shaped link 6c may be interchanged with the position of the L-shaped link 6d with respect to the front-rear direction so that configuration of the L-shaped links 6a, 6b, 6c and 6d and the support links 7a, 7b, 7c and 7d has symmetry with respect to a plane that runs along the central axes of the wheels 5a and 5b and that is orthogonal to the front-rear direction in the state in which the wheels 5a and 5b stop on the railroad track plane that is in a horizontal state.
In Embodiment 1, as illustrated in
In Embodiment 1, as illustrated in
Also, as illustrated in
As illustrated in
In the support portion illustrated in
As illustrated in
In Embodiment 3, the bearings 62 allow the links 51 and 61 to pivot relative to each other. The rubber bushing 53 enables relative inclinations of axes of the joint portions of the links 51 and 61 and absorption of an impact force transmitted from the railroad track plane to the vehicle body 1. Even if a pivot angle of the joint portion is relatively large, the bearings 62 enable problem-free pivoting. Additionally, anticipation is possible of an effect that is an ability to eliminate a repelling force occurring during pivoting and a frictional force occurring in the support portion.
As described above, in the vehicle wheel support device 70 according to each of the above embodiments, the support frames 4a and 4b supporting the wheels 5a and 5b in such a manner that the wheels 5a and 5b can roll on the rails are supported in such a manner that a change in distance between the wheels 5a and 5b and a change in angles with the railroad track plane which the wheels 5a and 5b make can be remarkably reduced using the L-shaped links 6a, 6b, 6c and 6d and the support links 7a, 7b, 7c and 7d. As a result, the present disclosure can, while maintaining conditions similar to generally-used wheels that are integrated with the wheel shaft, achieve a structure enabling both reduction of unsprung mass and the close proximity of a floor of a vehicle body between wheels to the railroad track plane.
The shapes of the support frames 4a and 4b are not limited to the shape of the letter “H”. For example, the support frames 4a and 4b may be shaped like the letter “U” by setting of distances between joint shafts in the L-shaped links, the support links and the support frames in accordance with lengths of the L-shaped links between support points on the vehicle body side. Alternatively, although each distance between support points in each L-shaped link is defined as described above, the shapes of the L-shaped links are not limited to the shape of the letter “L”, and the links may be shaped like an inverted “T”.
The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.
The present disclosure is used with advantage as a structure for supporting wheels of a low-floor vehicle separately from each other.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/060048 | 3/29/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/168546 | 10/5/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2477517 | Haynes | Jul 1949 | A |
| 3570408 | Lich | Mar 1971 | A |
| 3661097 | Jackson | May 1972 | A |
| 3774550 | Lich | Nov 1973 | A |
| 3817188 | Lich | Jun 1974 | A |
| 5546868 | Sugimoto | Aug 1996 | A |
| Number | Date | Country |
|---|---|---|
| 2000309268 | Nov 2000 | JP |
| 2015100249 | May 2015 | JP |
| Entry |
|---|
| International Search Report (PCT/ISA/210) dated May 17, 2016, by the Japan Patent Office as the International Searching Authority for International Application No. PCT/JP2016/060048. |
| Written Opinion (PCT/ISA/237) dated May 17, 2016, by the Japan Patent Office as the International Searching Authority for International Application No. PCT/JP2016/060048. |
| Number | Date | Country | |
|---|---|---|---|
| 20190084592 A1 | Mar 2019 | US |
